dagblog - Comments for "Brain structure differs in liberals, conservatives: study"

I'm sure they're just trying

Anonymous — Sat, 16 Apr 2011 22:18:49 +0000

I'm sure they're just trying to say that Conservatives are stupid. I mean it's not like they're gonna get any feedback on this from the Press, after all General Electric, Time Warner, The Walt Disney Co., and Viacom News Corporation are left wing coroprations who push liberal causes... I think this study shows why conservatives are cowardly science bashers who think everyone is out to get them! From my experence conservatives can't see the bigger picture and because they are easily confused and need a master to keep them honest they think everyone else does too.

Just something to think about

cmaukonen — Fri, 08 Apr 2011 19:20:10 +0000

In reply to Seems highly speculative.

Just something to think about is all.

Seems highly speculative.

Obey — Fri, 08 Apr 2011 18:00:33 +0000

In reply to Brain structure differs in liberals, conservatives: study

Seems highly speculative. They're assuming the covariation is transitive: that the covariation between self-assigned political labels and psychological traits on the one hand and between self-assigned political labels and neurological traits on the other hand implies a further co-variation between the psychological traits and the neurological traits. I.e. the subset of liberals who are, say, more open to new experiences may not overlap significantly with the subset of liberals with an increased volume of grey matter in the anterior cingulate cortex, and so on and so forth for all the various supposed psych and neuro traits. If they want to find out whether the relative openness of some liberals is linked to the relevant neuro trait, then they should test whether they correlate, and drop the intermediate term of self-assigned political labels altogether.

These guys have a great reputation, but this looks sloppy to me. Maybe I'm missing something in the original article, but I couldn't see anything in it to allay this kind of worry.

These findings are also

cmaukonen — Fri, 08 Apr 2011 16:04:49 +0000

In reply to Brain structure differs in liberals, conservatives: study

These findings are also interesting as well.

Childhood abuse and other extreme stressors can have lasting effects on brain areas involved in memory and emotion. The hippocampus is a brain area involved in learning and memory that is particularly sensitive to stress.^8,9 As reviewed in greater detail by Bruce McEwen in other Cyberounds high levels of glucocorticoids (cortisol in the human) released during stress were associated with damage to neurons in the CA3 region of the hippocampus, and a loss of neurons and dendritic branching.^10,11,12 Glucocorticoids disrupt cellular metabolism and increase the vulnerability of hippocampal neurons to excitatory amino acids like glutamate.¹³ Other neurochemical systems interact with glucocorticoids to mediate the effects of stress on memory and the hippocampus, including serotonin¹⁴ and brain-derived neurotrophic factor (BDNF).^15,16Stress also results in deficits in new learning that are secondary to damage to the hippocampus.^17,18 Exciting recent research has shown that the hippocampus has the capacity to regenerate neurons and that stress inhibits neurogenesis in the hippocampus.¹⁹

Studies in animals showing glucocorticoid-mediated hippocampal toxicity and memory dysfunction with stress raised the question: Does early stress, such as childhood abuse, result in similar deficits in human subjects? With this in mind, we used neuropsychological testing to measure declarative memory function in PTSD. We selected measures that were validated in studies of patients with epilepsy to be specific probes of hippocampal function. These neuropsychological measures (including delayed paragraph recall and word list learning) were correlated with a loss of neurons in the hippocampus in patients who underwent surgical resection of the hippocampus for the treatment of epilepsy.²⁰ We initially found verbal declarative memory deficits using similar measures in Vietnam combat veterans with PTSD.²¹

In the first report to use brain imaging in PTSD, combat veterans were found to have an 8% reduction in right hippocampal volume, measured with magnetic resonance imaging (MRI), with no difference in comparison regions including caudate, amygdala and temporal lobe (Figure 1).